Toropov, V.; Demyanova, E.; Shalaeva, O.; Sitkin, S.; Vakhitov, T. Whole-Genome Sequencing of Lactobacillus helveticus D75 and D76 Confirms Safety and Probiotic Potential. Microorganisms2020, 8, 329.
Toropov, V.; Demyanova, E.; Shalaeva, O.; Sitkin, S.; Vakhitov, T. Whole-Genome Sequencing of Lactobacillus helveticus D75 and D76 Confirms Safety and Probiotic Potential. Microorganisms 2020, 8, 329.
Whole-genome DNA sequencing of Lactobacillus D75 and D76 strains (Vitaflor, Russia) was performed using the PacBio RS II platform, followed by de novo assembly with SMRT Portal 2.3.0. The average nucleotide identity (ANI) test showed that both strains belong to the Lactobacillus helveticus, but not the L. acidophilus as previously assumed. 31 exopolysaccharide (EPS) production genes (nine of which form a single genetic cluster), 13 adhesion genes, 38 milk protein and 11 milk sugar utilization genes, 13 genes for and against specific antagonistic activity, aight antibiotic resistance genes, and also three CRISPR blocks and eight Cas I-B system genes were identified in the genomes of the both strains. The expression of some genes was confirmed. In fact, the presence of identified genes suggests that L. helveticus D75 and D76 are able to form biofilms on the outer mucin layer, inhibit the growth of pathogens and pathobionts, utilize milk substrates with the formation of digestible milk sugars and bioactive peptides, resist bacteriophages and show some genome-determined resistance to antibiotics, stimulate the host’s immune system. Pathogenicity genes have not been identified. The study results confirm the safety and high probiotic potential of the strains.
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